EQUATION
NOTE: The equations are often written
three times: (i) word equation, (ii) balanced symbol equation without state
symbols, and, (iii) with the state symbols (g), (l), (s) or (aq) to give the
complete balanced symbol equation.

All you need is a
selection of metals, water, universal indicator, rack of test tubes
and a splint.

Ideally all the metals
would be in the same physical state, other than all being solids,
i.e. same sized granules or same sized sheet of same thickness.
However this is isn't possible within a school laboratory (or its
budget!).

The experiment is
extremely easy to do, simply add small similar sized portions of the metal to
a few cm3 of cold
water containing a few drops of universal indicator.

Before adding the metal
the indicator should give a green colour indicating neutral ~pH 7.

Keep an eye on all of
them at the same time and note any changes and the relative rate of
evolution of gas bubbles.

Zinc is used in
galvanising, i.e. coating iron or steel to prevent rusting. The zinc
corrodes preferentially forming a protective oxide layer.

Tin's lack of reactivity
enables it to be used as a protective layer in steel cans of fruit -
tinned cans!

Lead's lack of
reactivity has enabled it in the past to be used for water pipes,
though it is being replaced by plastic tubing or piping for two
reasons - (i) lead is a toxic metal and plastic is cheaper!

Copper can be used for
roofing, where it corrodes superficially, and very slowly, to give a
green protective layer of a basic carbonate (its a mixture of
insoluble hydroxide and carbonate).

All you need is a
selection of metals, dilute hydrochloric acids, rack of test tubes
and a splint.

Ideally all the metals
would be in the same physical state, other than all being solids,
i.e. same sized granules or same sized sheet of same thickness.
However this is isn't possible within a school laboratory (or its
budget!).

The experiment is
extremely easy to do, simply add similar sized small portions of the metal to
a few cm3 of cold dilute hydrochloric acid.

Keep an eye on all of
them at the same time and note any changes and the relative rate of
evolution of gas bubbles.

If you strongly heat copper(II)
carbonate with finely powdered charcoal (mainly carbon) you can
reddish-brown specks of copper in resulting mixture. The dark
green copper(II) carbonate turns black initially as copper(II)
oxide is formed, but this is then reduced to copper by the
charcoal.

initially a thermal
decomposition: CuCO3 ==> CuO + CO2

then the reduction
reaction (O loss): 2CuO + C ==> 2Cu + CO2

You can of course start the
experiment with copper(II) oxide, but copper carbonate is closer
to the sort of naturally occurring copper ore that is mined.

You can do a similar experiment
by heating lead(II) oxide with powdered carbon and you can get
silvery lead formed BUT in a fume cupboard please, since lead
fumes are very poisonous!

2PbO + C ==> 2Pb + CO2

Lead is a sufficiently
unreactive metal for carbon to displace it.

If you heat iron oxides with
powdered carbon nothing happens however strongly you heat the
mixture in a test tube. Although carbon is reactive enough to
displace iron, the temperature in the test tube isn't high
enough - you need a blast furnace!